Re: [time-nuts] Making a Raspberry Pi NTP server without soldering
David, Thanks for posting and for all else that you post. You have done much with the Raspberry PI. How you done anything with or have compared the PI to the Beaglebone Black? Cheers, Graham ve3gtc -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of David J Taylor Sent: October-22-13 12:56 AM To: Time-nuts mailing list Subject: [time-nuts] Making a Raspberry Pi NTP server without soldering Many folk have asked about adding a GPS/PPS to the Raspberry Pi as an NTP server without soldering, and now that has become a reality thanks to the new NTPI GPS add-on board. Details: http://www.satsignal.eu/ntp/Raspberry-Pi-NTP.html#no-soldering The new u-blox GPS module 7Q is used, and you can use an external antenna. Cheers, David -- SatSignal Software - Quality software written to your requirements Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Making a Raspberry Pi NTP server without soldering
David, Thanks for posting and for all else that you post. You have done much with the Raspberry PI. How you done anything with or have compared the PI to the Beaglebone Black? Cheers, Graham ve3gtc == Graham, No I haven't, unfortunately. From what I read, I suspect that the BeagleBone Black may be a slightly better technical solution, but whether you could see any difference using them as stratum-1 NTP servers in a real environment I doubt. The Raspberry Pi has much greater support, and for a Linux newbie like me that is an important factor - I wouldn't have got as far as I have without help from the folk on this group and elsewhere. By the way, there are some dedicated NTP servers around which look to have a very much better performance, but they lack all the management and monitoring tools we have with NTP. For me, that was a deal breaker. Cheers, David -- SatSignal Software - Quality software written to your requirements Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Making a Raspberry Pi NTP server without soldering
On Tue, Oct 22, 2013 at 7:13 AM, Collins, Graham coll...@navcanada.cawrote: How you done anything with or have compared the PI to the Beaglebone Black? If your only use of the device is to have an NTP server then why pay more for the Beaglebone? The Pi based server seems to be better than required. better in this case meaning that it keeps time better then it can transfer it over your network. If you need a lower cost Linux server, you can repurpose a PogoPlug. These are roughly the same specs ARM process and a little bit of RAM but come with a case and power supply all for under $20. You can re-flash them with a general purpose Linix-ARM distribution. But no good place to attach a PPS input except for using a USB-Serial dongle. Well there is a serial port header inside the box but I've not tried it. Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Making a Raspberry Pi NTP server without soldering
The networking adapter on the Pi is connected to the SoC via USB while on the BeagleBone the MAC is native. I suspect this might affect timing. Andy Bardagjy bardagjy.com On Tue, Oct 22, 2013 at 11:36 AM, Chris Albertson albertson.ch...@gmail.com wrote: On Tue, Oct 22, 2013 at 7:13 AM, Collins, Graham coll...@navcanada.ca wrote: How you done anything with or have compared the PI to the Beaglebone Black? If your only use of the device is to have an NTP server then why pay more for the Beaglebone? The Pi based server seems to be better than required. better in this case meaning that it keeps time better then it can transfer it over your network. If you need a lower cost Linux server, you can repurpose a PogoPlug. These are roughly the same specs ARM process and a little bit of RAM but come with a case and power supply all for under $20. You can re-flash them with a general purpose Linix-ARM distribution. But no good place to attach a PPS input except for using a USB-Serial dongle. Well there is a serial port header inside the box but I've not tried it. Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Making a Raspberry Pi NTP server without soldering
David and Chris, Thanks for the comments. While my interest does include use as NTP server it is not entirely limited to that application, for example data collection and possibly RTL-SDR based ADS-B. I have spent much time searching for information on both devices and as David suggested, the Beaglebone Black has a bit more going for it technically but the raspberry PI has a much larger user base. I am considering one or the other or perhaps both to supplement my use of Arduino's and in light of the fairly recent announcement of the newest member of the Arduino stable in partnership with Intel I am wondering whether to wait for the new Aruduino offering (more $ but not much) or whether the PI or Beaglebone will do. See here for info on the Arduino Intel Galileo http://arduino.cc/en/ArduinoCertified/IntelGalileo Speaking of Arduino, I have still not posted my sketch for my very simple NTP client clock display. I should have known that when I dug out the code and started to clean it up a bit before posting that I would end up spending more time fussing over it. Soon. Cheers, Graham ve3gtc -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Chris Albertson Sent: October-22-13 11:36 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Making a Raspberry Pi NTP server without soldering On Tue, Oct 22, 2013 at 7:13 AM, Collins, Graham coll...@navcanada.cawrote: How you done anything with or have compared the PI to the Beaglebone Black? If your only use of the device is to have an NTP server then why pay more for the Beaglebone? The Pi based server seems to be better than required. better in this case meaning that it keeps time better then it can transfer it over your network. If you need a lower cost Linux server, you can repurpose a PogoPlug. These are roughly the same specs ARM process and a little bit of RAM but come with a case and power supply all for under $20. You can re-flash them with a general purpose Linix-ARM distribution. But no good place to attach a PPS input except for using a USB-Serial dongle. Well there is a serial port header inside the box but I've not tried it. Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Making a Raspberry Pi NTP server without soldering
David, This is definity on my to build list. I have picked up the Pi already. (Have had it for 9 months) Did fire it up and start the process. But the wwvb d-psk-r is using up the free time. I will get to this. So thank you for the posts appreciated greatly. Regards Paul WB8TSL On Tue, Oct 22, 2013 at 11:47 AM, Collins, Graham coll...@navcanada.cawrote: David and Chris, Thanks for the comments. While my interest does include use as NTP server it is not entirely limited to that application, for example data collection and possibly RTL-SDR based ADS-B. I have spent much time searching for information on both devices and as David suggested, the Beaglebone Black has a bit more going for it technically but the raspberry PI has a much larger user base. I am considering one or the other or perhaps both to supplement my use of Arduino's and in light of the fairly recent announcement of the newest member of the Arduino stable in partnership with Intel I am wondering whether to wait for the new Aruduino offering (more $ but not much) or whether the PI or Beaglebone will do. See here for info on the Arduino Intel Galileo http://arduino.cc/en/ArduinoCertified/IntelGalileo Speaking of Arduino, I have still not posted my sketch for my very simple NTP client clock display. I should have known that when I dug out the code and started to clean it up a bit before posting that I would end up spending more time fussing over it. Soon. Cheers, Graham ve3gtc -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Chris Albertson Sent: October-22-13 11:36 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Making a Raspberry Pi NTP server without soldering On Tue, Oct 22, 2013 at 7:13 AM, Collins, Graham coll...@navcanada.ca wrote: How you done anything with or have compared the PI to the Beaglebone Black? If your only use of the device is to have an NTP server then why pay more for the Beaglebone? The Pi based server seems to be better than required. better in this case meaning that it keeps time better then it can transfer it over your network. If you need a lower cost Linux server, you can repurpose a PogoPlug. These are roughly the same specs ARM process and a little bit of RAM but come with a case and power supply all for under $20. You can re-flash them with a general purpose Linix-ARM distribution. But no good place to attach a PPS input except for using a USB-Serial dongle. Well there is a serial port header inside the box but I've not tried it. Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Making a Raspberry Pi NTP server without soldering
No, you are talking microseconds on a system with millisecond performance. The data will go through Ethernet switches and routers and then whatever networking gear is on your clients too. Today many of the clients will be WiFi. The figure of merit here is the timing on the client computers. MAC only effects the clients. These clients are typically at the handful of milliseconds level. NTP measures the round trip delay over the local network so the things that mess up timing are (1) Asymmetric speed because NTP assume the one way delay is exactly half the round trip and (2) Variation in the delay. So a fixed long latency is just fine but a lot of variation is not.On a typical network #2 will be the dominate factor that you can't control. It might be effected by things like if someone is watching a YouTube video or if a file backup is going on. Yes the USB link to the MAC would add variation in the timing but other sources of error are 1000 times bigger. (like for example the OS has a queue Ethernet packets.) You have to look at the purpose of your NTP server. It is so that all the computers have a common system time so that file time stamps and log file entries can be matched up. How the MAC connects is kind of like worrying if the chrome platting in that little hook on your tape measure has a well controlled plating thickness. Yes of course it matters, just not enough to worry about because all the other error sources are much larger. On Tue, Oct 22, 2013 at 8:38 AM, Andy Bardagjy a...@bardagjy.com wrote: The networking adapter on the Pi is connected to the SoC via USB while on the BeagleBone the MAC is native. I suspect this might affect timing. Andy Bardagjy bardagjy.com On Tue, Oct 22, 2013 at 11:36 AM, Chris Albertson albertson.ch...@gmail.com wrote: On Tue, Oct 22, 2013 at 7:13 AM, Collins, Graham coll...@navcanada.ca wrote: How you done anything with or have compared the PI to the Beaglebone Black? If your only use of the device is to have an NTP server then why pay more for the Beaglebone? The Pi based server seems to be better than required. better in this case meaning that it keeps time better then it can transfer it over your network. If you need a lower cost Linux server, you can repurpose a PogoPlug. These are roughly the same specs ARM process and a little bit of RAM but come with a case and power supply all for under $20. You can re-flash them with a general purpose Linix-ARM distribution. But no good place to attach a PPS input except for using a USB-Serial dongle. Well there is a serial port header inside the box but I've not tried it. Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Making a Raspberry Pi NTP server without soldering
David and Chris, Thanks for the comments. While my interest does include use as NTP server it is not entirely limited to that application, for example data collection and possibly RTL-SDR based ADS-B. I have spent much time searching for information on both devices and as David suggested, the Beaglebone Black has a bit more going for it technically but the raspberry PI has a much larger user base. I am considering one or the other or perhaps both to supplement my use of Arduino's and in light of the fairly recent announcement of the newest member of the Arduino stable in partnership with Intel I am wondering whether to wait for the new Aruduino offering (more $ but not much) or whether the PI or Beaglebone will do. See here for info on the Arduino Intel Galileo http://arduino.cc/en/ArduinoCertified/IntelGalileo Speaking of Arduino, I have still not posted my sketch for my very simple NTP client clock display. I should have known that when I dug out the code and started to clean it up a bit before posting that I would end up spending more time fussing over it. Soon. Cheers, Graham ve3gtc = Graham, You well know that something better will always be along in six month's time, so why not wait six months and use it. Oh, but something better still will be available then! So you never get anything actually done! HI! I expect you may have seen my notes on an ADS-B program (written by Malcolm Robb): http://www.satsignal.eu/raspberry-pi/dump1090.html and on monitoring ambient temperature: http://www.satsignal.eu/raspberry-pi/monitoring.html#ambient so those may prove of interest. There's obviously work to do on the temperature monitoring as the program doesn't trap either no data returned (0°C) or max value returned (85°C IIRC), but it demonstrates a capability. To me there's something good about having one device per function, but the Pi is capable of more than that. Looking forward to your Arduino code! 73, David GM8ARV -- SatSignal Software - Quality software written to your requirements Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Making a Raspberry Pi NTP server without soldering
albertson.ch...@gmail.com said: How the MAC connects is kind of like worrying if the chrome platting in that little hook on your tape measure has a well controlled plating thickness. Yes of course it matters, just not enough to worry about because all the other error sources are much larger. I think that's misleading. USB is polled. That adds a layer of jitter. There are probably some systematic errors too. When you send a packet, it leaves synchronized with the USB clock. The return packet will also be synchronized with that clock so the return network time will be rounded up to the next clock tick with no jitter. It would be interesting to see if we can measure it. Besides, this is time-nuts. We pay attention to that sort of detail. But I agree that if all you are interested in is having reasonable time on nearby PCs a few ms won't matter. -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Making a Raspberry Pi NTP server without soldering
Yes it is polled. But polled at what rate? It adds jitter but the figure of merit is the jitter in the system clock at the client side. How much does this USB polling degrade the client's clock? On Tue, Oct 22, 2013 at 11:48 AM, Hal Murray hmur...@megapathdsl.netwrote: albertson.ch...@gmail.com said: How the MAC connects is kind of like worrying if the chrome platting in that little hook on your tape measure has a well controlled plating thickness. Yes of course it matters, just not enough to worry about because all the other error sources are much larger. I think that's misleading. USB is polled. That adds a layer of jitter. There are probably some systematic errors too. When you send a packet, it leaves synchronized with the USB clock. The return packet will also be synchronized with that clock so the return network time will be rounded up to the next clock tick with no jitter. It would be interesting to see if we can measure it. Besides, this is time-nuts. We pay attention to that sort of detail. But I agree that if all you are interested in is having reasonable time on nearby PCs a few ms won't matter. -- These are my opinions. I hate spam. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Making a Raspberry Pi NTP server without soldering
Many folk have asked about adding a GPS/PPS to the Raspberry Pi as an NTP server without soldering, and now that has become a reality thanks to the new NTPI GPS add-on board. Details: http://www.satsignal.eu/ntp/Raspberry-Pi-NTP.html#no-soldering The new u-blox GPS module 7Q is used, and you can use an external antenna. Cheers, David -- SatSignal Software - Quality software written to your requirements Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
